Maintaining the temperature of items whose temperatures differ from their environment has always been a challenge. Thermal insulation containers, commonly referred to as "coolers," are frequently used when one cannot use refrigeration units and wishes to keep items cooler than surrounding temperatures. Conventional coolers are commonly made from insulated hard plastic containers having either hinged or fully removable lids. These coolers are typically large and bulky. Additionally, although often waterproof, and therefore useable with ice, conventional coolers are rigid and heavy, rendering them undesirable for transporting or using while engaging in outdoor activities such as biking, hiking, rafting, or kayaking. The interior storage areas of conventional coolers can also be difficult to clean before and after use and are further difficult to dry after use.
In an effort to overcome these drawbacks of conventional coolers, some manufacturers have produced soft coolers. While these soft coolers are pliable and lighter than their conventional predecessors, they typically are not waterproof and are therefore designed to be used with ice substitutes. Conventional ice substitutes come in various forms. An example of one such substitute comprises a sealed package of gel-like material that solidifies when frozen. The sealed package is placed in the cooler with the contents where the ice substitute package keeps the environment within the container cool for a finite period of time. Although providing for a moderate degree of cooling, ice substitutes are not as effective as real ice. First, there is little or no direct contact between the ice substitute and the contents of the cooler. Ice, on the other hand, maintains direct contact with the articles to be cooled thereby providing greater heat transfer. Additionally, upon melting, ice transforms to ice water which remains in direct contact with those contents, providing continued heat transfer. Therefore, the use of an ice substitute results in less heat transfer than that which occurs when ice is used, making ice a more preferable cooling medium.
With the forgoing disadvantages of the prior art in mind, it is an object of the present invention to provide a thermally insulative container for cooling articles that is light, easily portable, pliable and facilitates the use of ice.
It is another object of the present invention to provide such an apparatus that is inexpensive as well as easy to clean and dry.
It is a further object to provide a thermally insulative container designed to easily fit within a secondary carrying apparatus, such as conventional backpacks.
Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.